Audio systems sometimes include one or more acoustic transducers to convert acoustic signals into electrical signals (e.g., microphones) to detect acoustics in the environment in which they operate, and sometimes also include acoustic drivers (e.g., loudspeakers) to reproduce acoustic audio content from an electrical signal. Microphones may be deployed in such systems for the purpose of detecting desired audio, which may include a user's speech for applications such as automatic speech recognition, virtual personal assistants, and communications (e.g., telephone), for example. The microphone(s) may pick up components of the audio playback generated by the acoustic drivers, e.g., through acoustic reflections and/or acoustic coupling, etc., and this self-playback (echo) signal may interfere with the detection and/or processing of the desired signal, e.g., the user's speech. Echo cancellers having adaptive filters may be used to reduce or remove the echo signal components.